When heavy objects are shipped in transport vehicles, the responsible parties may be liable for shipping damage incurred while the objects are in transit. Rail shipments are subjected to a known level of routine shocks such as during humping of rail cars wherein a car is accelerated to a minimum speed in order to effect joining, and locking, of cars together as trains are built at the railroad switchyard. Thus, any plan for loading and/or packing of items into the rail car must provide satisfactory shock absorbing dunnage material, in a satisfactory loading arrangement, to protect the items from being damaged by routine operation of the railroad such as humping.
Parent rolls of paper web, as produced on a papermaking machine, are large and heavy. Such rolls typically weigh over 1000 pounds, and may weigh as much as several thousand pounds.
For shipping, these massive rolls are placed on end, with the transverse direction of the web material disposed vertically, such that the outer layer of paper in each roll comprises a cylindrically defined upstanding wall thereabout.
For rail shipment, the rolls are generally arranged in two arrays disposed generally on opposite ends of the rail car. The rolls in each array are generally in abutting engagement with each other, and with respective walls of the rail car, with conventional dunnage and other bracing members between ones of the rolls and between rolls and walls of the rail car, as needed to cushion the rolls, and to bring a first set of rolls in the first array into proximate but spaced and facing relationship with a second set of rolls in the second array at the doorway, which is centrally located in the rail car.
Such arrays are well known and conventionally used. In such conventional use, each array is generally firmly embraced by the combination of the respective sidewalls and the end wall of the rail car, and the conventional cushioning dunnage elements used between individual rolls and between ones of the rolls and the side and end walls of the rail car.
Given the above, the rolls in each array are fixedly secured, with respect to the corresponding side walls and end wall on the respective end of the car, against movement inside the rail car in response to impact shocks imparted to the rail car during normal transport. However, the space between the first and second sets of rolls at the doorway needs to be filled with dunnage to control movement of the first and second sets of rolls at the doorway, and to unitize/tie the two arrays to each other to thereby effectively combine all the rolls in the rail car into a single overall array. Such control of the first and second sets of rolls is, further, imperative to maintaining the unity of each of the arrays, such that individual ones of the rolls are unable to react individually to shipping shocks.
Thus, in an ideal transport situation, the combination of all the rolls in the rail car acts as a single unit. To the extent the arrays can be linked to each other through proper use of dunnage, the two arrays, in combination, act as a single unit. To the extent the two arrays act as a single unit and the end arrays are immovably embraced by the side and end walls of the rail car, significant movement of the rolls relative to each other and relative to the walls of the rail car, is prevented. To the extent movement of the rolls can be controlled, shipping damage is correspondingly controlled.
It is known to fixedly secure a bracing system to the floor of the rail car. However, parent rolls of paper are manufactured in a variety of sizes, which require a variety of packing patterns in the rail car, and thus a relatively versatile bracing system at the doorway. Accordingly, fixedly securing a bracing system to the floor of the rail car is inefficient for such application.
It is known to use inflatable air bags between facing rolls. In such use, after the rolls are in place, the bag is positioned between the rolls and then inflated to about 8-10 pounds per square inch gauge (psig) pressure. In one such use, a single bag is positioned vertically with respect to each set of facing rolls as shown in Prior Art FIG. 1.
In a second such use, the bag is laid down horizontally, filling the space between all the facing rolls, and is then inflated as shown in Prior Art FIG. 2. If the paper rolls of the load extend above the horizontally-disposed bag, a second bag may be placed and inflated above the first bag.
In either case of the above prior art assemblages, the surfaces of the bag, as inflated, tend to follow the contours of the respective adjacent rolls. When force is exerted on the outside of the bag by e.g. a shock, the bag distributes the force partially against the adjacent rolls, but in significant amount by expanding the enlarged, bulging ends of the bag. In the case of FIG. 2, the bag also expands/bulges at its central portion as shown, into the respective cavities between adjacent ones of the rolls. To the extent the bag can disperse the shock by further expansion or bulging of the bag, the bag may not effectively resist movement of the roll. Thus, movement of the roll is not effectively controlled. The bag and the rolls shift. Damage to both the rolls and the bag can result. To the extent the bag is damaged, of course, the bag fails in its primary role of cushioning the rolls.
It is known in e.g. Cottone U.S. Pat. No. 4,854,792 to use a single contour buffer pad as a spacing device between each and every roll, in the shipment and wherein the rolls are disposed in a single straight line between opposing ends of the rail car. It is also known to use buffer pads selectively between rolls. The pad as disclosed in Cottone includes a base sheet, and embracing shoulder pads on each edge of the base sheet, wherein the shoulder pads on a given side of the base sheet are spaced to embrace a single given roll of product at two spaced loci displaced from each other about the circumference of the roll, with the central portion of the base sheet therebetween.
West U.S. Pat. No. 4,572,716 uses a bracing system comprising a pair of single-sided contour buffer pads against each of two rolls, with an inflated air bag between the two buffer pads. As in Cottone, West addresses each two facing rolls separately, and does not address the issue of how to link together, and thereby to stabilize, and generally to immobilize the two pairs of rolls at the doorway of the rail car. As in Cottone, the West buffer pads address only a loading pattern wherein the rolls are aligned in straight lines between opposing ends of the rail car.
The teachings of known references are limited to cushioning rolls aligned in straight lines between ends of the rail car. But the diameters of the rolls may not accommodate an efficient straight-line loading pattern in the rail car. For example, it is now common to ship paper rolls 42-55 inches in diameter. Given the typical width of the rail car of e.g. 114-116 inches, efficient loading of such rolls suggests using offset loading patterns. Offset loading patterns transfer longitudinally-imposed shocks on the car into transversely directed forces acting on and through the rolls. Accordingly, cushioning dunnage material should provide for, and thus control, such transverse forces in the load. It is especially important that no transverse force be imposed on the door of the rail car.
This invention is directed toward providing improvements in devices and methods for stabilizing, and generally immobilizing facing sets of movable massive objects in a rail car such that all the units act as a single array, generally by linking the respective massive objects together using linking bracing members, and improving the effectiveness of an associated air bag in transferring shock within the so-built single array.
Thus it is an object of the invention to provide a dunnage wedge to be placed in the cavity between first and second rolls of a side-by-side pair of rolls, and thereby to impede bulging of the air bag into the cavity.
It is another object to provide a bracing system between first and second facing pairs of rolls, including a first wedge in the first cavity, a second wedge in the second cavity, and an inflatable bag disposed between the two pairs of rolls, inflated against the respective ones of the rolls and the wedges.
It is still another object to provide a bracing system wherein the inflatable bag has a generally uniform thickness across the faces of the two pairs of rolls, and generally is precluded from entering the respective cavities between the rolls.